bims-microg 2025-12-14 papers

bims-microg

Biomed News

on Microglia in health and disease

Issue of 2025–12–14
nineteen papers selected by
Marcus Karlstetter, Universität zu Köln

Shape-shifting microglia respond to neuronal hyperexcitability.
Dynamic changes in mitochondria support phenotypic flexibility of microglia.
Microglia and Myeloid Cell Populations of the Developing Mouse Retina.
Acute neuroinflammation induces prolonged transcriptional reprogramming in microglia.
Mitochondria are absent from microglial processes performing surveillance, chemotaxis, and phagocytic engulfment.
Hyperglycemia impairs microglia responding to retinal vasculopathy via enhanced norepinephrine-ADRB2 signaling.
Microglial Fkbp5 Impairs Post-Stroke Vascular Integrity and Regeneration by Promoting Yap1-Mediated Glycolysis and Oxidative Phosphorylation.
Microglia-derived APOE2 improves remyelination even in the presence of endogenous APOE4.
Mertk promotes early microglial-mediated synaptic engulfment in Alzheimer's disease.
Chimeric human organoid and mouse brain slice co-cultures to study microglial function.
Repetitive unidirectional spinal tactile stimulation engages microglial Bmal1 pathways to promote synaptic remodeling in the mPFC of adolescent VPA-exposed mice.
The SARS-CoV-2 nucleocapsid protein induces microglia senescence-mediated cognitive impairment via Glycolysis.
Revisiting Primary Microglia Isolation Protocol: An Improved Method for Microglia Extraction.
SIRT2 Inhibition promotes microglia LC3-associated phagocytosis via NRF2/CD36 after the experimental subarachnoid hemorrhage.
Sweet orange essential oil and (+)-limonene prevent oxidative stress, reduce inflammation, and apoptosis in differentiated SH-SY5Y neuroblastoma/BV-2 microglia co-culture neurodegeneration models.
Single-cell transcriptomics reveals probiotic reversal of neonatal morphine-induced gene disruptions underlying adolescent pain hypersensitivity.
Canagliflozin inhibits NLRP3 Inflammasome activation to protect the Retinal Neurovascular Unit in a Mouse Retinal Vein Occlusion Model.
Neural stem cell transplantation attenuates cognitive decline and neuroinflammation in a mouse model of Alzheimer's disease with chronic cerebral hypoperfusion.
Lifestyle shapes preclinical social and microglial deficits in an Alzheimer's disease mouse model.

Immunity. 2025 Dec 09. pii: S1074-7613(25)00504-7. [Epub ahead of print]58(12): 2927-2930

Shape-shifting microglia respond to neuronal hyperexcitability.

Clara Alice Musi, Diego Gomez-Nicola.

The initial responses of microglia to neuronal stress or altered network activity are poorly characterized. Xie and colleagues show that during TDP-43-related neurodegeneration, microglia detect early neuronal hyperactivity and transition into a distinct rod-shaped state. This study uncovers a microglial state that precedes overt neuronal loss, shedding new light on the earliest stages of neurodegeneration.

DOI: https://doi.org/10.1016/j.immuni.2025.11.002
Nat Commun. 2025 Dec 12. 16(1): 11103

Dynamic changes in mitochondria support phenotypic flexibility of microglia.

Katherine Espinoza, Ari W Schaler, Daniel T Gray, Arielle R Sass, Adrian Escobar, Kamilia Moore, Megan E Yu, Casandra G Chamorro, Lindsay M De Biase.

Microglial capacity to adapt to tissue needs is a hallmark feature of these cells. New studies show that mitochondria critically regulate the phenotypic adaptability of macrophages. To determine whether these organelles play similar roles in shaping microglial phenotypes, we generated transgenic mouse crosses to accurately visualize and manipulate microglial mitochondria. We find that brain-region differences in microglial attributes and responses to aging are accompanied by regional differences in mitochondrial mass and aging-associated mitochondrial remodeling. Microglial mitochondria are also altered within hours of LPS injections and microglial expression of inflammation-, trophic-, and phagocytosis-relevant genes is strongly correlated with expression of mitochondria-relevant genes. Finally, direct genetic manipulation of microglial mitochondria alters microglial morphology and leads to brain-region specific effects on microglial gene expression. Overall, this study advances our understanding of microglial mitochondria and supports the idea that mitochondria influence basal microglial phenotypes and phenotypic remodeling that takes place over hours to months.

DOI: https://doi.org/10.1038/s41467-025-66709-5
Glia. 2026 Feb;74(2): e70115

Microglia and Myeloid Cell Populations of the Developing Mouse Retina.

Sage Martineau, Juan C Valdez-Lopez, Samantha Zarnick, Jeremy N Kay.

  Microglia make important contributions to central nervous system (CNS) development, but the breadth of their distinct developmental functions remains poorly understood. The mouse retina has been a key model system for understanding fundamental mechanisms controlling the assembly of the CNS. To gain insight into where and how microglia might influence retinal development, here we identified molecularly unique myeloid cell populations that are selectively present during development and characterized their anatomical locations. Development-specific transcriptional states were identified using single-cell (sc) and single-nucleus RNA-sequencing (RNA-seq) across multiple timepoints. Transcriptional states were validated in vivo by histological staining for key RNA and/or protein markers. Several of these development-specific myeloid populations have been described before in brain scRNA-seq atlases but not validated in vivo, while others are unique to our retinal dataset. We identify two closely related microglial populations, labeled by the Spp1 and Hmox1 genes, that are distinguished mainly by transcriptional targets of the NRF2 transcription factor. Both types are present selectively within the developing retinal nerve fiber layer where they engulf neurons and astrocytes undergoing developmental cell death. Hmox1+ microglia were also localized selectively at the wavefront of developing vasculature during retinal angiogenesis, suggesting that developmental events associated with angiogenesis modulate NRF2 activity and thereby induce microglia to switch between the Spp1+ and Hmox1+ states. Overall, our results identify transcriptional profiles that define specific populations of retinal microglia, opening the way to future investigations of how these programs support microglial functions during development.

Keywords:  efferocytosis; macrophage; osteopontin; phagocytosis; single‐cell sequencing; vascular development

DOI:  https://doi.org/10.1002/glia.70115
J Neuroinflammation. 2025 Dec 10.

Acute neuroinflammation induces prolonged transcriptional reprogramming in microglia.

Sehoon Moon, Cheol Gyun Kim, Young-Kwang Kim, Cheol-Heui Yun, Min-Kyoo Shin, Hyungseok Seo.

  Acute neuroinflammation rapidly activates brain immune responses, but its lasting effects on microglia are unclear. Using systemic LPS administration and LCMV-Armstrong infection, we found that blood-brain barrier disruption and cytokine shifts resolved within 30 days, yet microglial recovery was incomplete-marked by persistent numerical loss and an IFN-γ-low phenotype in the LPS model and reduced relative abundance in the LCMV model. Single-cell RNA sequencing revealed sustained transcriptional alterations, including disease-associated microglia (DAM) features and a distinct recovery-biased population. These acute signatures overlapped with profiles from Alzheimer's model mice and were enriched in human microglia from multiple sclerosis, Alzheimer's disease, and other neuroinflammatory conditions. Although our observation period was shorter than the chronic course of these diseases, the persistence of disease-like microglial states suggests that transient inflammation can prime the brain for long-term vulnerability. Targeting this primed state may offer new strategies to prevent or mitigate neurodegenerative pathology.

Keywords:  Acute neuroinflammation; Microglia; Transcriptomic reprogramming

DOI:  https://doi.org/10.1186/s12974-025-03572-7
Nat Commun. 2025 Dec 12. 16(1): 11104

Mitochondria are absent from microglial processes performing surveillance, chemotaxis, and phagocytic engulfment.

Alicia N Pietramale, Xhoela Bame, Megan E Doty, Kiera E Schwarz, Robert A Hill.

Microglia continually surveil the brain allowing for rapid detection of tissue damage or infection. Microglial metabolism is linked to tissue homeostasis, yet how mitochondria are subcellularly partitioned in microglia and dynamically reorganize during surveillance, injury responses, and phagocytic engulfment in the intact brain are not known. Here, we performed intravital imaging and ultrastructural analyses of microglia mitochondria in mice and human tissue, revealing that microglial processes diverge in their mitochondrial content, with some containing multiple mitochondria while others are completely void. Microtubules and hexokinase 2 mirror this uneven mitochondrial distribution indicating that these cytoskeletal and metabolic components are linked to mitochondrial organization in microglia. Microglial processes that engage in minute-to-minute surveillance typically do not have mitochondria. Moreover, unlike process surveillance, mitochondrial motility does not change with animal anesthesia. Likewise, the processes that acutely chemoattract to a lesion site or initially engage with a neuron undergoing programmed cell death do not contain mitochondria. Rather, microglia mitochondria have a delayed arrival into the responding cell processes. Thus, there is subcellular heterogeneity of mitochondrial partitioning. Moreover, microglial processes that surveil and acutely respond to damage do not contain mitochondria.

DOI: https://doi.org/10.1038/s41467-025-66708-6
J Neuroinflammation. 2025 Dec 08.

Hyperglycemia impairs microglia responding to retinal vasculopathy via enhanced norepinephrine-ADRB2 signaling.

Shimiao Bu, Bin Mou, Zongqin Xiang, Liting Zhang, Binjie Hao, Junliang Chen, Lang Huang, Xiangcai Ruan, Yong U Liu, Yuehong Zhang.

  Breakdown of the blood-retina barrier is a key event in the progression of retinal vascular diseases. Microglia, the resident immune cells of the retina and central nervous system, respond rapidly to vascular injury, yet how hyperglycemia affects this protective function remains unclear. In this study, we combined intravitreal injection of lipopolysaccharide (LPS) with streptozotocin to mimic both acute inflammation under hyperglycemic conditions. LPS triggered a robust increase in microglia-blood vessel interactions (MVIs), mediated by P2Y12 receptor signaling, as confirmed by both pharmacological inhibition and genetic knockout of P2Y12. Live ex vivo retinal imaging demonstrated that microglial processes rapidly converged on injured vessels within 30 min in a P2Y12-dependent manner. However, four weeks of hyperglycemia significantly blunted this MVI response. We found that hyperglycemia elevated circulating norepinephrine (NE), which infiltrated the retina and suppressed MVIs through activation of microglial β2-adrenergic receptors (ADRB2). Ex vivo imaging further showed that pharmacological ADRB2 activation impaired microglial process convergence to sites of vascular injury. Together, these findings reveal that NE-ADRB2 signaling antagonizes P2Y12-mediated microglial engagement with leaky vessels, contributing to BRB breakdown. This study uncovers a novel neuroimmune-vascular mechanism by which hyperglycemia compromises retinal vascular repair and identifies potential therapeutic targets for retinal vascular disorders.

Keywords:  ADRB2; Blood-retina barrier; Microglia; Norepinephrine; Retinal vessel

DOI:  https://doi.org/10.1186/s12974-025-03647-5
Adv Sci (Weinh). 2025 Dec 08. e12499

Microglial Fkbp5 Impairs Post-Stroke Vascular Integrity and Regeneration by Promoting Yap1-Mediated Glycolysis and Oxidative Phosphorylation.

Yanan Li, Yanmei Qiu, Yunlei Yang, Yanhao Wei, Haokun Peng, Longhai Zeng, Pengcheng Li, Rentang Bi, Bo Hu.

  The role of microglia in blood-brain barrier (BBB) leakage and neovascularization after ischemic stroke remains unclear. Here, a post-stroke perivascular niche of microglia characterized by low expression of M2 markers and elevated glycolysis, oxidative phosphorylation (OXPHOS), and phagocytic activity is identified, which is termed stroke-activated vascular-associated microglia (stroke-VAM). It is found that Fkbp5 acts as a central regulator driving BBB disruption and impaired neovascularization through stroke-VAM. Single-nucleus RNA sequencing (snRNA-seq) analysis of Cx3cr1Cre Fkbp5flox/flox (Fkbp5 cKO) mice in the ipsilateral hemisphere reveals enhanced interactions between stroke-VAM and endothelial cells, influencing signaling pathways that maintain BBB integrity and promote neovascularization. After ischemic injury, microglia in Fkbp5 cKO mice exhibits higher M2 marker expression and reduces glycolysis, OXPHOS, and phagocytosis, resulting in decreased BBB leakage and enhanced angiogenesis. Mechanistically, unbiased snRNA-seq analysis shows that the Hippo signaling pathway is altered in Fkbp5 cKO stroke-VAM. Fkbp5 inhibits Yap1 phosphorylation, facilitating its nuclear translocation. These findings provide new insights into how the perivascular microglial niche contributes to both the degradation and regeneration of cerebral vasculature, offering potential therapeutic avenues for acute ischemic stroke.

Keywords:  BBB; Fkbp5; ischemic stroke; neovascularization; vascular associated microglia

DOI:  https://doi.org/10.1002/advs.202512499
J Neuroinflammation. 2025 Dec 11.

Microglia-derived APOE2 improves remyelination even in the presence of endogenous APOE4.

Georgia L Nolt, Lesley R Golden, Shealee P Thorpe, Jessica L Funnell, Isaiah O Stephens, Gabriela Hernandez, Steven M MacLean, Chloe C Lucido, Chesney R Brock, Akhil V Pallerla, Darcy R Adreon, Holden C Williams, Josh M Morganti, Lance A Johnson.

  Demyelination occurs with aging and is exacerbated in neurodegenerative diseases. During demyelination, microglia upregulate expression of APOE, the gene encoding for the brain's primary lipid transport protein apolipoprotein E (ApoE), which also mediates microglial engulfment and elimination of myelin debris. Compared to the E3 allele of APOE, the E2 allele decreases risk for Alzheimer's disease (AD), while the E4 allele increases AD risk and is associated with an increased severity and progression of multiple sclerosis. Previous work shows that mice expressing E2 exhibit improved microglial function and remyelination compared to mice expressing E4. However, whether microglial-derived APOE is responsible for driving these differences following demyelination, and if microglia-selective expression of E2 is sufficient to provide protection, is unknown. We sought to determine if microglia-specific replacement of the E4 allele with E2 can rescue myelin loss and promote remyelination, even in the presence of continued E4 expression by other central nervous system (CNS) cells. Using a novel APOE allelic "switch" model in which we can induce a replacement of E4 with E2 exclusively in microglia, we characterize the glial cell response and lipid profile of mice that underwent either lysophosphatidylcholine (LPC) or cuprizone (CPZ)-induced demyelination and subsequent remyelination. We found that although alterations to the brain lipid profile were subtle, microglial E2 replacement significantly improved remyelination, lessened microgliosis, and decreased astrocytic lipid droplet load following CPZ-remyelination. Our results indicate that microglia-specific E2 expression, in the presence of continued E4 expression, may provide protection against myelin loss via both cell-autonomous and non-autonomous immunometabolic mechanisms.

Keywords:  Apolipoprotein E; Brain; Gliosis; Lipid metabolism; Microglia; Myelination

DOI:  https://doi.org/10.1186/s12974-025-03639-5
Theranostics. 2026 ;16(3): 1238-1261

Mertk promotes early microglial-mediated synaptic engulfment in Alzheimer's disease.

Yifan Wu, Yuanteng Fan, Shisan Bao, Yinghao Song, Ruizhu Wang, Jiaxuan Wu, Xuan Liu, Jingwen Jin, Lingchen Kong, Baohua Hou, Peiyu Liang, Taoxiang Chen, Wanhong Liu, Biwen Peng, Fanggang He, Ying Zhou, Jian Xu, Yun Chen, Song Han, Jun Yin, Xiaohua He.

  Rationale: Synaptic deficits occur prior to the emergence of Aβ plaques and tau pathology in Alzheimer's disease (AD). Dysregulated microglia excessively prune synapses, leading to synaptic loss. While microglia phagocytic receptor Mertk participates in synaptic pruning, the role of Mertk in driving early synaptic loss in AD remains elusive. Methods: Single-cell RNA sequencing (scRNA-seq) was used to analyze transcriptional changes of microglia in early stage of AD mice. Mertk-mediated synaptic engulfment was investigated both in vivo and in vitro. Results: Phagocytic-associated microglia with upregulated Mertk were identified in the early stage of AD mice. Dysregulated synaptic pruning by microglia caused hippocampal synaptic loss and memory deficits in two AD mouse models. Notably, Mertk knockout or antagonist treatment reversed excessive synapse elimination by microglia. Mechanistically, Aβo-induced PPARγ promoted Mertk transcription, mediating microglial phagocytosis of synapses. Conclusions: Collectively, our findings suggest that PPARγ-regulated, Mertk-mediated microglial synaptic engulfment contributes to early synaptic loss in AD, highlighting microglial Mertk as a potential therapeutic target for AD.

Keywords:  Alzheimer's disease; Mertk; PPARγ; microglia; synaptic engulfment

DOI:  https://doi.org/10.7150/thno.116797
Cell Rep. 2025 Dec 10. pii: S2211-1247(25)01428-7. [Epub ahead of print]44(12): 116656

Chimeric human organoid and mouse brain slice co-cultures to study microglial function.

Vasiliki Panagiotakopoulou, Marc Welzer, Olmo Ruiz Ormaechea, Diana Werner, Lena Erlebach, Anika Bühler, Ulrike Obermüller, Jonas J Neher, Mathias Jucker, Deborah Kronenberg-Versteeg.

  Studying the dynamic role of microglia in brain development and neurodegenerative diseases requires models that closely resemble the human brain environment. While human induced pluripotent stem cell (iPSC)-derived organoids (hORGs) effectively reproduce key neuronal and certain glial cell types, modeling human microglia in vitro remains challenging. Inspired by recent approaches demonstrating enhanced microglial maturation in hORGs transplanted into mouse brains, we develop a chimeric model by co-culturing hORGs with mouse brain slice cultures (mBSCs). This system reveals cross-species interactions associated with an earlier onset of cortical neuronal differentiation markers in the hORGs. Human iPSC-derived microglia, pre-differentiated in mBSCs, migrate into the hORGs and adopt ramified morphology. They remain viable for several months and respond to laser-induced injury, demonstrating long-term functionality. This in vitro model supports long-term study of human microglia in a brain-like environment, providing a platform for mechanistic studies and screening compounds that target microglial function.

Keywords:  CP: neuroscience; CP: stem cell research; cerebral organoids; chimeric in vitro model; human microglia; xenotransplantation

DOI:  https://doi.org/10.1016/j.celrep.2025.116656
J Neuroinflammation. 2025 Dec 11.

Repetitive unidirectional spinal tactile stimulation engages microglial Bmal1 pathways to promote synaptic remodeling in the mPFC of adolescent VPA-exposed mice.

Yi-Nan Chen, Sha-Tong Zhao, Ming-An Hu, Wu Li, Juan Yu, Meng-Juan Ma, Li-Ya Tang, Xiang Feng, Yu-Xing Zhang, Jiang-Shan Li.

   BACKGROUND: Synaptic abnormalities are hallmark pathological features of autism spectrum disorders (ASD), contributing to the behavioral impairments frequently observed in these neurodevelopmental conditions. Microglia, as the brain's primary immune cells, are essential for synaptic refinement during adolescent development. Disrupted microglia-dependent synapse remodeling has been implicated in pathophysiology of ASDs, however, the underlying mechanisms remain incompletely elucidated. In this context, repetitive unidirectional spinal tactile stimulation (RSTS) has emerged as a promising non-invasive therapeutic strategy. This study aims to explore whether and how RSTS enhances microglia-dependent synapse remodeling in the medial prefrontal cortex (mPFC) during adolescent development in ASD mice, with a specific focus on the role of Brain and Muscle ARNT-Like 1 (Arntl1), a core circadian protein crucial for regulating this process.
METHODS: ASD mice underwent RSTS treatment during adolescent brain for 21 days, administered twice daily for 10 min per session. Behavioral changes were evaluated using the three-chamber social interaction and open field tests. Synapse number and morphology were assessed through Golgi staining. Microglia-dependent synapse remodeling ability was analyzed using immunofluorescence and Western blot. Furthermore, the molecular mechanism was investigated using single-nucleus RNA sequencing (snRNA-seq) and chromatin immunoprecipitation sequencing (ChIP-seq). Finally, the role of Bmal1 was validated, confirming its involvement in the enhancement of RSTS during adolescent brain in ASD.
RESULTS: RSTS was found to alleviate autistic-like behaviors in adolescent ASD mice. Results from snRNA-seq and ChIP-seq indicated that the therapeutic effects of RSTS may be mediated through microglial Bmal1 and its role in the transcriptional regulation of microglia-dependent synapse remodeling. Furthermore, in vivo experiments confirmed that RSTS enhances microglia-dependent synapse remodeling in mPFC of adolescent ASD mice via Bmal1. These findings suggested that Bmal1 serves as a critical target of RSTS in facilitating microglia-dependent synapse remodeling during the adolescent brain developmental period in ASD mice.
CONCLUSION: Our findings suggest that the therapeutic effects of RSTS are potentially mediated through the modulation of microglial Bmal1-dependent synapse remodeling and the regulation of synaptic proteins and the complement system. These results provide novel empirical evidence for RSTS in restoring synaptic balance and offer valuable insights into its potential as an intervention for ASD.

Keywords:  Autism spectrum disorder༛Microglia-dependent synapse remodeling༛Bmal1༛Adolescent brain development; Repetitive unidirectional spinal tactile stimulation

DOI:  https://doi.org/10.1186/s12974-025-03627-9
Mol Med. 2025 Dec 12.

The SARS-CoV-2 nucleocapsid protein induces microglia senescence-mediated cognitive impairment via Glycolysis.

Nan-Shi-Yu Yang, Han-Xi Sha, Chen-Yu Zhang, Hui Chen, Yu-Biao Liu, Jian-Bing Xiong, Jia-Xi Duan, Jun Zhang, Cha-Xiang Guan, Yong Zhou, Feng Su, Wen-Jing Zhong.

  The COVID-19 pandemic has precipitated a surge in neurocognitive dysfunction, with long-term implications for global health systems and socioeconomic stability. Despite growing clinical recognition of post-COVID cognitive deficits ("brain fog"), the molecular mechanisms driving these impairments remain poorly understood. Our study addresses this critical gap by identifying SARS-CoV-2 nucleocapsid protein (SARS-CoV-2 N protein), a core structural component of the virus, as a novel etiological factor in senescence-mediated cognitive decline. We observed that SARS-CoV-2 N protein caused microglial senescence both in vivo and in vitro. Mechanistically, SARS-CoV-2 N protein-induced metabolic shifting toward glycolysis initiated a cascade of microglial senescence, which propagated cognitive impairment. We found that glycolysis inhibition reduced SARS-CoV-2 N protein-triggered microglial senescence and attenuated cognitive impairment in mice. Disrupted mitochondrial dynamics impaired oxidative phosphorylation capacity, forcing glycolytic reprogramming that ultimately triggered cellular senescence activation. We found that the SARS-CoV-2 N protein promoted excessive mitochondrial dysfunction in microglia, resulting in mitochondrial fragmentation. Inhibition of mitochondrial fission effectively rescued SARS-CoV-2 N protein-induced microglial senescence. In conclusion, our study suggests that the SARS-CoV-2 N protein induces senescence-mediated cognitive impairment by promoting glycolysis in microglia. Therapeutic targeting of glycolysis in SARS-CoV-2 N protein-triggered microglial senescence could be beneficial for treating or preventing cognitive impairment.

Keywords:  Cognitive impairment; Glycolysis; Microglia; SARS-CoV-2 N protein; Senescence

DOI:  https://doi.org/10.1186/s10020-025-01410-3
Bio Protoc. 2025 Dec 05. 15(23): e5530

Revisiting Primary Microglia Isolation Protocol: An Improved Method for Microglia Extraction.

Jianwei Li, Zijian Zheng, Menglin Zhang, Cheng Xue, Xinran Zhang, Guohui Lu.

  Microglia, the resident immune cells of the central nervous system, play a crucial role in maintaining neural homeostasis and in regulating neurodevelopment, neuroinflammation, tissue repair, and neurotoxicity. They are also key contributors to the pathogenesis of various neurodegenerative disorders, underscoring the need for in vitro models that accurately recapitulate disease-relevant conditions. Among the available isolation methods, the classical mixed glial culture shaking technique remains the most commonly employed, while alternatives such as magnetic bead separation and fluorescence-activated cell sorting (FACS) offer higher purity but are often constrained by technical complexity and cost. In this study, we refined the traditional shaking method by supplementing specific cytokines during culture to enhance microglial viability and proliferation. Our optimized protocol produced primary microglia with higher purity, greater yield, and improved viability compared with the conventional approach, thereby increasing experimental efficiency while substantially reducing time, animal usage, and overall cost. Key features • The microglial cells obtained using this protocol achieve a purity of approximately 90%. • This protocol maximizes the viability of primary microglial cells. • The entire procedure requires a minimum of 9 days to complete. • Antibiotic or antifungal solutions are not used in this protocol.

Keywords:  Cell culture; Microglial isolation; Parkinson’s disease model; Primary microglia; SNCA A53T transgenic mice

DOI:  https://doi.org/10.21769/BioProtoc.5530
J Neuroinflammation. 2025 Dec 12.

SIRT2 Inhibition promotes microglia LC3-associated phagocytosis via NRF2/CD36 after the experimental subarachnoid hemorrhage.

Bin Sheng, Xiangxin Chen, Tao Tao, Jiaqing Sun, Wei Li, Lingyun Wu, Zheng Peng, Xiaojian Li, Zhengxu Zhou, Qian Yu, Yeping Ling, Prativa Sherchan, Jerry J Flores, Jiping Tang, Lei Huang, Chunhua Hang, John H Zhang.



Keywords:  LAP; Microglia; Phagocytosis; SIRT2; Subarachnoid hemorrhage

DOI:  https://doi.org/10.1186/s12974-025-03623-z
BMC Complement Med Ther. 2025 Dec 09.

Sweet orange essential oil and (+)-limonene prevent oxidative stress, reduce inflammation, and apoptosis in differentiated SH-SY5Y neuroblastoma/BV-2 microglia co-culture neurodegeneration models.

Edina Pandur, Loretta Heilmann, Margita Szilágyi-Utczás, Tibor Rák, Katalin Sipos, Adrienne Csutak, Györgyi Horváth.

   BACKGROUND: Parkinson's disease (PD) is becoming increasingly prevalent worldwide. The pathophysiology of this condition is characterized by oxidative stress, inflammation, iron accumulation, mitochondrial dysfunction, and protein aggregation, all of which contribute to cell death and neurodegeneration. Microglia, the innate immune cells of the brain, play a significant role in the development and progression of PD by releasing inflammatory cytokines upon activation. Essential oils (EOs) are emerging as potential therapeutic agents because of their antioxidant and anti-inflammatory properties.
METHODS: In our study, we investigated the antioxidant, anti-inflammatory, and anti-apoptotic effects of sweet orange [Citrus sinensis (L.) Osbeck (Rutaceae)] EO and its main compound (+)-limonene on monocultures of all-trans retinoic acid-differentiated and 6-hydroxydopamine-induced (6-OHDA) SH-SY5Y cells and bilaminar co-cultures containing differentiated and 6-hydroxydopamine-induced SH-SY5Y cells and BV-2 microglia.
RESULTS: Sweet orange EO and (+)-limonene significantly decreased reactive oxygen species (ROS) production and increased oxidative stress defense by increasing the total antioxidant capacity and glutathione peroxidase and superoxide dismutase activities in human neuroblastoma (SH-SY5Y) cells. Additionally, both EO and its main compound mitigated inflammation by downregulating the secretion of pro-inflammatory cytokines. They also decreased the cytochrome c levels and caspase-3 activity. Furthermore, sweet orange EO and (+)-limonene attenuated microglia-mediated inflammation in co-cultures, suggesting their potential application as modulators of microglial activity.
CONCLUSIONS: Based on these results, sweet orange EO and its main component, (+)-limonene, can be considered as neuroprotective agents and are promising candidates for complementary therapy in Parkinson's disease.

Keywords:  (+)-limonene; Antioxidant capacity; Caspase-3; Oxidative stress; Pro-inflammatory cytokines; Sweet orange essential oil

DOI:  https://doi.org/10.1186/s12906-025-05215-z
Commun Biol. 2025 Dec 10. 8(1): 1757

Single-cell transcriptomics reveals probiotic reversal of neonatal morphine-induced gene disruptions underlying adolescent pain hypersensitivity.

Junyi Tao, Danielle Antoine, Richa Jalodia, Eridania Valdes, Sean Michael Boyles, William Hulme, Sabita Roy.

Neonatal morphine is commonly administered in the Neonatal Intensive Care Unit (NICU) to manage pain. However, its long-term effects on the neurodevelopment of pain pathways remain a significant concern. The midbrain is a core region that plays a central role in pain processing and opioid-mediated analgesia. Here, we perform single-cell RNA sequencing to study gene expression in 107,427 midbrain single cells from adolescent mice neonatally exposed to either saline, morphine, or morphine with the probiotic Bifidobacterium infantis (B. infantis) for 5 days starting on postnatal day 6-7. We find broad alterations in transcriptomics within neurons, astrocytes, oligodendrocytes, and microglial cells. Analysis of differentially regulated genes reveals down regulation of HOX genes and upregulation of pathways related to neurotransmitter signaling and pain in those adolescent mice neonatally treated with morphine. Interestingly, neonatal probiotic supplementation mitigates these morphine-induced alterations on the transcriptome. This study presents the first single-cell RNA sequencing dataset of the adolescent midbrain following neonatal morphine exposure and probiotic intervention. These findings offer new insights into the neurodevelopmental impact of early opioid exposure and highlight the therapeutic potential of microbiome-targeted interventions.

DOI: https://doi.org/10.1038/s42003-025-09150-0
Exp Eye Res. 2025 Dec 09. pii: S0014-4835(25)00576-7. [Epub ahead of print] 110803

Canagliflozin inhibits NLRP3 Inflammasome activation to protect the Retinal Neurovascular Unit in a Mouse Retinal Vein Occlusion Model.

Jixian Ma, Xuan Liu, Yazhou Qin, Yuyao Qu, Qiuping Liu, Jingming Li.

  To investigate whether Canagliflozin exerts a protective effect on the neurovascular units (NVUs) in a mouse retinal vein occlusion (RVO) model by inhibiting NLRP3 inflammasome activation, we establish a laser-induced RVO model in C57BL/6J mice and administer a Canagliflozin-containing diet. Retinal non-perfusion (RNP) formation is assessed via fundus fluorescein angiography (FFA). Retinal flat-mount immunofluorescence staining is used to detect microglial activation and retinal ganglion cells (RGCs) loss. Frozen-section immunofluorescence staining evaluates Müller glial cell activation, while TUNEL staining on frozen sections detects RGCs death. Western blotting is employed to analyze vascular leakage and NLRP3 inflammasome activation. Results demonstrated that Canagliflozin reduced RNP formation, inhibited albumin leakage, attenuated glial cells activation, mitigated RGCs loss, and suppressed NLRP3 inflammasome activation in RVO mice, independent of its hypoglycemic and weight-reducing effects. These findings suggested that Canagliflozin protected the retinal NVUs in a mouse RVO model by inhibiting NLRP3 inflammasome activation.

Keywords:  Canagliflozin; NLRP3 inflammasome; Neurovascular unit; Retinal vein occlusion; Sodium-glucose cotransporter 2 inhibitor

DOI:  https://doi.org/10.1016/j.exer.2025.110803
J Cereb Blood Flow Metab. 2025 Dec 09. 271678X251400239

Neural stem cell transplantation attenuates cognitive decline and neuroinflammation in a mouse model of Alzheimer's disease with chronic cerebral hypoperfusion.

Zhicheng Lu, Hong Zhou, Haibo Tang, Shiyu Luo, Jie Wang, Xingwu Zheng, Yuanhong Hu, Qiuyan Qin, Chengmin Yang, Shenglong Mo, Xiaorui Huang, Lina Tang, Bing Huang, Weishan Xu, Jingtang Nong, Guangqing Gan, Donghui Qin, Zhao Peng, Chongdong Jian, Xia Liu, Xuebin Li, Jingwei Shang.

  Alzheimer's disease (AD) and chronic cerebral hypoperfusion (CCH) frequently coexist in aging populations, synergistically aggravating neurodegeneration. To assess the therapeutic potential of stem cell interventions, an AD + CCH mouse model was generated by combining APP/PS1 mice with bilateral common carotid artery stenosis. Neural stem cells (NSCs) or induced pluripotent stem cells (iPSCs) were transplanted into the lateral ventricles at 5 months of age. Behavioral testing, Nissl staining, Western blotting, and immunofluorescence were conducted at 9 and 12 months to evaluate cognition, neuronal survival, cell death pathways (LC3-II, cleaved caspase-3, NLRP3), glial polarization, and neurotrophic/synaptic markers (BDNF, VEGF, VAChT, PSD95). CCH exacerbated AD-related cognitive deficits, neuronal loss, and activation of autophagic, apoptotic, and pyroptotic pathways, accompanied by enhanced M1 microglial polarization, astrogliosis, and downregulation of BDNF and VAChT. NSCs transplantation significantly improved cognitive performance, preserved neuronal integrity, attenuated glial activation, and restored neurotrophic and synaptic protein expression, characterized by increased BDNF, VEGF, and PSD95 levels and partial recovery of VAChT. In contrast, iPSCs transplantation failed to exert comparable effects. These findings demonstrate that NSCs, but not iPSCs, mitigate AD + CCH-induced neuropathology by re-establishing the balance between inflammatory, neurotrophic, and synaptic signaling, supporting NSCs as a promising therapeutic approach for AD with vascular comorbidity.

Keywords:  Alzheimer’s disease; chronic cerebral hypoperfusion; induced pluripotent stem cells; microglia polarization; neural stem cells

DOI:  https://doi.org/10.1177/0271678X251400239
Mol Psychiatry. 2025 Dec 12.

Lifestyle shapes preclinical social and microglial deficits in an Alzheimer's disease mouse model.

Fanny Ehret, Birte Doludda, Hang Liu, Sindi Nexhipi, Hao Huang, Fabian Rost, Rupert W Overall, Warsha Barde, Annette E Rünker, Michael Sieweke, Andreas Dahl, Mirko H H Schmidt, Gerd Kempermann.

Alzheimer's disease has a long preclinical phase, during which no overt signs of the manifest disease are present, but subtle, usually non-specific changes are already detectable. Emerging early biomarkers underscore the importance of this phase for preventive measures including lifestyle interventions. As a reductionistic model for lifestyle factors, we used a novel enrichment paradigm in which AppNL-G-F knock-in mice were continuously tracked until 7 months of age. Despite minimal plaque burden and no memory impairment at that age, there were early and progressive deficits in social parameters - such as following behavior, social interaction, and exploration - suggesting preclinical behavioral vulnerability. Altered correlations between adult neurogenesis and social parameters linked neural plasticity to preclinical behavior. Plasma profiling at 3 months identified early systemic shifts in markers of inflammation and apoptosis that predicted later cortical pathology. We found increased microglia coverage in more socially active animals. More actively exploring controls, but not AppNL-G-F mice, exhibited more ramified and less amoeboid microglia, suggesting that AD pathology impairs immune surveillance at a very early stage. Single-cell RNA sequencing of hippocampal microglia revealed that enrichment dampened interferon-responsive microglia, which typically increase as amyloidosis advances. A shifted immune response was also measured by reduced transcripts related to antigen processing and presentation and by increased chemokine signaling. Our study demonstrates that the preclinical phase of AD is not silent, but even in a reductionistic knock-in model characterized by early interwoven preclinical changes in multiple domains, including brain plasticity, behavioral trajectories, sociality and immunity.

DOI: https://doi.org/10.1038/s41380-025-03368-4